Water supply in Hong Kong before 1860s mainly relied on primitive sources such as wells and streams. Since the mid-nineteenth century, the continual increase in population and the accompanying city expansion had placed a great pressure on permanent provision of fresh water resources which accelerated the construction of reservoirs. The first water supply scheme was mooted during the time Sir Hercules Robinson was the Governor of Hong Kong from 1859 to 1865. Completed in 1863, Pok Fu Lam Reservoir is the first ever-built reservoir in the territory.